The present invention relates to a method and apparatus for use in inspecting an article having discontinuities in a surface of the article.
Although the method and apparatus of the present invention may be utilized to inspect many different types of articles. In one specific instance, the method and apparatus are utilized to inspect cores which are utilized to form an interior space in an airfoil. Known cores are illustrated in U.S. Pat. Nos. 5,580,837 and 7,624,787. These known cores and other known cores may be utilized to form a space within an airfoil in the manner disclosed in U.S. Pat. No. 5,738,493.
In the past, cores have been inspected by manually checking cores on a nominal center/form. An individual inspecting the core visually evaluates distortion which appears in a checking section portion of the center/form. This known method involves manual fixing and human interpretation.
Some known cores have had dedicated laser point inspection fixtures which inspect the core displacement at individual points, usually a maximum of five places. These known laser point inspection methods have not provided an inspection of a surface of the core.
Aircraft airfoils cost structure, core type, and volume makes inspecting the cores 100% via coordinate measuring machines or white light non cost effective. Improvements in the design and construction of setter inspections and in relates processes have improved contour inspection capability, but the inherent design and method of using setter blocks can allow unacceptable cores to pass inspection.